Field of the Invention
The present invention relates to attachment structures for actuator-specific solenoid valves and actuator-equipped valves and in particular an attachment structure for an actuator-specific solenoid valve and an actuator-equipped valve exceptionally suitable for ALD process.
Description of the Related Art
In recent years, as semiconductor manufacture process, the introduction of ALD (Atomic Layer Deposition) process has been developed. In the ALD process, in an atmosphere at high temperatures (approximately 200 degrees Celsius), gases of a plurality of types such as a precursor, an inert gas, and an oxidizing species gas are alternately supplied from a gas supply system to a chamber by high-speed switching of an extremely short cycle, and atomic layers are homogeneously and uniformly stacked one by one at a nano level on a wafer in the chamber to form a thin film. As a valve for use in this gas supply system, in view of advantages in air operation and valve characteristics and so forth, a direct diaphragm valve including a pneumatic actuator is often adopted.
On the other hand, in the above-described valve open/close operation (air pressure operation by the actuator), a solenoid valve for switching a compressed air flow path with excitation of the solenoid by electrification is interposed between an air supply source for supplying compressed air and the actuator, and air operation is often performed by this solenoid valve. Generally in this case, the solenoid valve is connected via a long air ductwork such as an air tube at a position away from the actuator (cylinder), and the actuator and the solenoid valve are separately and individually configured away from each other.
With the interposition of the long air ductwork linking between the actuator and the solenoid valve, a loss occurs in time by a volume in this long ductwork until the operation air reaches the actuator, thereby degrading responsivity of the actuator with respect to switching operation of the solenoid valve. It particular, this problem is significant in the ALD process in which extremely high quick reaction is required with high-speed switching and also the gas flow rate per switching is small.
By contrast, Japanese Patent Nos. 5054904 and No. 6166855 are suggested as prior arts in which an air operated actuator (cylinder) and a solenoid valve for switching this actuator are made into an integrally adjacent and integrated structure via a predetermined solenoid valve attachment structure, thereby minimizing or eliminating a ductwork distance provided therebetween, improving responsivity between the actuator and the solenoid valve and valve maintainability and, in particular, providing favorable characteristics to the ALD process.
Japanese Patent No. 5054904 (refer to FIG. 1 and paragraph 0036) discloses a diaphragm valve including an attachment structure in which for the purpose of enhancing responsivity of open/close operation of a valve by more decreasing a space part of a fluid passage for driving, a solenoid valve for controlling circulation of a fluid (air) for driving to be supplied into a pneumatic actuator is directly fixed to the upper surface of the actuator to eliminate an air ductwork.
Japanese Patent No. 6166855 discloses an attachment structure for an operation-specific solenoid valve for supplying an operation fluid. In this suggested attachment structure, with an attachment screw in a predetermined structure having an inner flow path, an attachment block in a predetermined structure can be directly fixed via a seal member to an operation port which is open to a cylinder upper surface side, thereby closely fixing the solenoid valve on the cylinder upper surface side.
In addition to the above, there is also a valve product with an attachment structure capable of rotatably fixing a solenoid valve to a side surface of an actuator via a fixture for fixing the solenoid valve to the actuator.